KR890005012B1 - Magnetic disk apparatus - Google Patents

Abstract

The magnetic disc driver comprises the drive motor (2) for imparting rotation to the magnetic disc (1) and the head transport motor (8) for moving the magnetic heads (5,6) radially. The drive motor and the head transport motor receive power from a common direct current supply terminal via two switching transistors which independantly control the power delivery to the two motors for effectively saving power. In order to prevent the flow of a surge current, the conduction retarder is empolyed which responds to an actuating signal received from the host disc controller.

Description

Magnetic disk device

1 is a block diagram of a magnetic disk device in accordance with an embodiment of the present invention.

2 is a partial circuit diagram of a magnetic disk device of a variation.

* Explanation of symbols for main parts of the drawings

(1): Magnetic disk (2): Disk rotating motor

(5) (6): Magnetic head (8): Stepping motor for head movement

(18): power supply terminal 20: first transistor

21: second transistor 22: voltage stabilized capacitor

23: inrush current preventing capacitor 24: first on control circuit

25: second on control circuit

The present invention relates to a floppy disk device or similar magnetic disk device for recording and playing back information using a magnetic disk.

Since the magnetic disk device is controlled by the host side, there is no power switch. Therefore, when the power switch on the host side is in the ON state, the real power supply voltage is always supplied to the magnetic disk device, which inevitably increases the power consumption.

In order to solve this drawback, the applicant has proposed a method of selectively blocking a power line of a part of a magnetic disk device according to Korean Patent Application Nos. 4520/84 and 4521/84. However, a method of quickly recording and reproducing and saving power has not been proposed yet.

Accordingly, an object of the present invention is to provide a magnetic disk device capable of quickly starting recording and reproducing, simultaneously saving power, and providing a stable voltage supply.

The present invention for achieving the above object is a disk rotating mechanism including a disk rotating motor for rotating a magnetic disk, a magnetic head for recording and reproducing information using the magnetic disk, the head in the radial direction of the disk A head moving mechanism including a head moving motor for moving, and a second transistor connected between the DC power terminal and the disk rotating motor, and a second transistor connected between the DC power terminal and the head moving motor Of the transistor, a first on control circuit for supplying an on control signal of the first transistor when the disk rotating motor is turned on, and a second transistor for supplying a predetermined voltage to the head moving motor. A capacitance larger than that of the second on control circuit for supplying the control signal and the output side circuit of the second transistor; A capacitor for stabilizing the power supply line voltage connected to the output terminal of the first transistor, and a transistor for operating the first transistor so that its on resistance gradually decreases when the first transistor is switched from an off state to an on state. It relates to a magnetic disk device composed of a movable control circuit.

In the present invention configured as described above, since a voltage stabilizing capacitor is connected to the output side of the first transistor, an inrush current is intended to flow into the capacitor by the ON control of the first transistor. Since it is controlled to decrease gradually, the inrush current for the capacitor is controlled. As a result, the current of the power supply line due to the inrush current is controlled. As a result, the voltage drop of the power supply line due to the inrush current is reduced, thereby reducing the adverse effect on the power supply terminal and other related loads. If a voltage stabilizing capacitor is provided and the inrush current is prevented again, there will be a delay in supplying power to the disk rotating motor. However, in the magnetic disk apparatus, a time of about 0.1 s-1 s is usually required until the disk reaches a predetermined rotation, and the delay caused by preventing the inrush current of the capacitor is not so problematic. On the other hand, the head move operation (seek operation) must be a quick operation and move one track about 1ms to 40ms after the step command (head move command) from the host is output. As in the conventional apparatus, if the head moving motor is always connected to the power source, the head can be moved quickly by the head moving command. However, when the power supply of the head moving motor is controlled to the off or low voltage state due to power saving, it is necessary to start the power supply quickly. In the device of the present invention, the capacitance of the circuit of the output side of the second transistor is less than that of the circuit of the output side of the first transistor, and since the second transistor does not delay-on-driving, the voltage required for the head movement motor is quickly obtained. Can be supplied. The first transistor controls the power supply to the disk rotating motor and the second transistor controls the power supply to the head moving motor, so that the power supply can be controlled independently and the power saving effect can be enhanced. .

EXAMPLE

Next, a magnetic disk device according to an embodiment of the present invention will be described with reference to FIG. In Fig. 1, reference numeral 1 denotes a flexible magnetic disk, which is generally called a floppy disk. Reference numeral 2 denotes a disk rotating motor constituting the disk rotating mechanism, which rotates the disk 1 along with the spindle 3 and the hub 4. Reference numerals 5 and 6 denote magnetic heads for recording information on the disk 1 and reading information from the disk 1, and are supported by the carriage 7. Moreover, one head 5 is detached from the disk when the disk is not inserted, and is supported to be connected to the disk when the disk 1 is inserted, and the other head 6 is fixedly supported. Reference numeral 8 denotes a stepping motor as a head moving mechanism, which drives the carriage 7 via a α-steel belt or a rotation-linear motion converter mechanism (not shown) such as pinion and rack. It is.

Furthermore, the carriage 7 is guided to move the heads 5, 6 in the radial direction of the disc 1. The stepping motor 8 for the head movement has, in this embodiment, first, second, third and fourth windings 9, 10, 11 and 12, each of which has a common end. It is connected to the NAND gates 13, 14, 15, and 16 of the off-collector type at the other end of each other. Reference numeral 17 is a phase control circuit, which controls the output of the designated NAND gate at low level in response to the step signal, and allows current to flow through the designated winding. Reference numeral 18 is, for example, a + 12V DC power supply terminal. Reference numeral 20 is a first transistor and is connected between the power supply terminal 18 and the disk rotation motor 12. Reference numeral 21 is a second transistor and is connected between the power supply terminal 18 and the head moving stepping motor 18. Reference numeral 22 is a voltage stabilizing capacitor, and is connected between the power supply line on the output side of the first transistor 20 and the ground (common line). The capacitance of the capacitor 22 is set to be larger than all the capacitance (stray capacity or the capacitance of the capacitor connected to the output side circuit of the second transistor 21. Reference numeral 23 is A capacitor constituting the transistor startup control circuit, and connected between the collector and the base of the first transistor 20. Reference numeral 24 denotes a first on-control circuit, It is connected to the base and generates a control signal when driving the disc rotation motor 2. Reference numeral 25 is a second on control circuit, connected to the base of the second transistor 21, and stamping mow. An on control signal is generated when a voltage is supplied to the rotor 8. Reference numeral 26 denotes a write and read circuit, which performs signal processing on the signal lines of the magnetic heads 5 and 6. Moreover, this write and read is performed. Circuit 26 has a first transistor Is connected to 20. The reference numeral 27 is the input voltage stabilizing capacitor is connected between the power supply terminal 18 and ground.

In the disk device of FIG. 1, when the on control signal is generated from the first on control circuit 24 of the floppy disk controller by the motor on signal lamp, the first transistor 20 is turned on. At this time, since the start delay capacitor 23 is provided, the first transistor 20 does not turn on rapidly but turns on slowly as if the on resistance gradually decreases. As a result, even when the voltage stabilizing capacitor 22 with a relatively large capacity is provided, a large inrush current does not flow and a significant drop in the power supply voltage does not occur. If an inrush current flows to the capacitor 22 and a sudden voltage drop occurs, a terminal device such as a display device, a CPU, etc., commonly connected to the power supply terminal 18, may operate incorrectly. Is prevented. When the first transistor 20 is turned on, the motor 2 rotates and the disk 1 also rotates. Since the mechanical delay of the rotation of the disk in the disk rotating mechanism is relatively large, the delay of the on time of the first transistor 20 is not so problematic. The write and read circuit 26 is also connected to the first transistor 20, so that the write and read circuit 26 writes and reads data unless the supply voltage is supplied late but does not rotate to the normal state of the disc 1; Is not done, so no problem occurs. When an on control signal is output from the second on control circuit 25 in response to a seek command or the like, the second transistor 21 is turned on, a voltage is supplied to the stepping motor 8, and the windings 9 to ˜ are supplied. Current flows into the selected place in (12). Since the second transistor 21 does not have an on delay circuit, the second transistor 21 is quickly turned on, the stepping motor 8 is driven, and the heads 5 and 6 are quickly moved on the desired track of the disk 1. Move.

As is apparent from the above description, the apparatus of the present embodiment has the following advantages.

(A) Independently controlled by two transistors 20 and 21 which differ in power from the disk rotation motor 2 and the head movement stepping motor 8, power supply suitable for each circuit can be provided. Recording or playback can be started quickly.

(B) Because of the power saving, the disk rotation motor 2 and the head movement stepping motor 8 can be turned off independently without turning on at the same time, so that the power saving can be controlled finely.

(C) Even if the ON control signal is simultaneously applied to the first and second transistors 20 and 21, a difference occurs in the on time, so that the total starting current decreases.

[Modification]

The present invention is not limited to the above-described embodiment, and the following modifications are possible, for example.

(a) As shown in FIG. 2, the power supply terminal 29 of the second voltage (+ 5V) is connected to the output terminal of the second transistor 21 through the reverse current blocking diode 28. The supply of + 12V by (18) and the supply of + 5V by the line 29 may be selectively performed. In FIG. 2, + 5V is supplied to the stepping motor 8 during the period in which the second transistor 21 is turned off, and the stepping motor 8 is driven low current so as to maintain the designated head position. The second transistor 21 is turned on, the drawing diode 28 is turned off, + 12V is supplied to the stepping motor 8, and the stepping motor 8 can perform the step operation. Furthermore, in FIG. 2, the same reference numerals are given to the parts supplied with the first diagram.

(b) As shown in FIG. 2, the time constant circuit 30 for gradually increasing the base current may be connected to the base circuit of the first transistor 20. FIG.

(c) If necessary, a capacitor having a smaller capacity than that of the capacitor 22 can be connected to the output terminal of the second transistor 21.

(d) The transistors 20 and 21 may be used as field effect transistors.

Claims (2)

A disk rotating mechanism including a disk rotating motor 2 for rotating the magnetic disk 1, magnetic heads 5 and 6 for recording or reproducing information using the magnetic disk 1; And a head moving mechanism including a head moving motor 8 for moving the heads 5 and 6 in the radial direction of the disk 1, a DC power supply terminal 18 and the disk rotating motor 2. ), A first transistor 20 connected between the first transistor 20, a second transistor 21 connected between the DC power supply terminal 18 and the head movement motor 8, and the disk rotation motor. When a predetermined voltage is supplied to the first on control circuit 24 and the head movement motor 8 to supply an on control signal to the first transistor 20 at the time of driving (2). A second on control circuit 25 for supplying an on control signal to the second transistor 21 to the second transistor 21; A power supply voltage voltage stabilizing capacitor 22 connected to an output side of the first transistor 20 having a capacitance value larger than that of the output side circuit of the second transistor 21; Magnetic disk device comprising a transistor start adjusting circuit 23 or 30 for starting the first transistor 20 such that its on-resistance gradually decreases when switching from the off state of the transistor 20 to the on state. . 2. The magnetic disk device according to claim 1, wherein the start adjustment circuit is a capacitor (23) connected between a collector and a base of the first transistor (20).

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